This invention pertains to rotary equipment, pedestal-mounted, and in particular to rotary equipment, such as vertical, centrifugal pumps suspended on pedestals which have the equipment or pump driver located, on the pedestal, directly above the equipment or pump.
In the aforedescribed arrangements, where the rotary equipment, or the centrifugal pump is pedestal-suspended, with the driver therefor directly above, vibration problems, under certain conditions, arise. In particular, this problem occurs when the arrangement comprises a variable speed, drive for the equipment or pump.
What has been needed is some means for increasing the stiffness of the driver-supporting pedestal, so as to move the natural frequencies of the rotary equipment and the pedestal out of the operating speed range for the driver and rotary equipment. It would be useful if there were some means for changing the natural frequency mode shape of the pump or other rotary equipment.
This invention sets forth means for increasing the stiffness of the driver pedestal to move the natural frequencies out of the operating speed range. Too, the invention discloses a means which changes the natural frequency mode shape of the subject pump or other rotary equipment.